Airplane safety device



April 1, 1952 M. v. PILCHER AIRPLANE SAFETY DEVICE Filed March 27, 1946 SUPPLY m w R H T E s w 3 a6 PULL PUSH -OPEN L CLOSE PUSH OPEN sky 9 4g: 4

Patented Apr. 1, i952 OFFICE AIRPLANE SAFETY DEVICE Matt V. Pilcher, Sarasota, Fla. Application March 27, 1946, Serial No. 657,555

8 Claims. 1

This invention relates to airplane safety devices, and more particularly aims to provide an improved device to prevent the pilot from taking ofi while the gasoline supply is cut off.

Heretofore there have been frequent accidents caused by failure of the pilot to turn on the gasoline supply valve before the take-01f, resulting in power failure at the critical moment of leaving the ground. Such accidents have been possible since there usually is enough gasoline in the carburetor and supply pipes to enable the pilot to get off the ground without turning on the supply from the gasoline storage tanks, particularly if the airplane has just landed and needs no extended warm-up. The resulting power failure, of course, causes a forced landing, and the very grave possibility of serious injury.

The primary object of the present invention, therefore, is to provide a construction which will prevent movement of the throttle to take-off position so long as the gasoline supply valve remains closed.

A further object is to provide a construction in which the airplane engine may be started without turning on the gasoline supply, but in which the natural manipulation of the throttle lever by the pilot will assure its becoming locked in non-take off position if the gasoline supply is not turned on.

A further object is to provide a construction in which the throttle must be moved to a nontake off position before the gasoline supply valve can be moved to oil position, and in which the throttle cannot be moved to take-01f or substantially open position until the gasoline supply valve is moved to the open or on position.

Further objects and advantages of the invention, as will appear from the following description of preferred embodiments thereof, reside in the provision of improved features and arrangements of parts contributing to the realization of the aforesaid objects.

In the accompanying drawings of preferred embodiments illustrative of the invention:

Fig. 1 is a front elevation of a portion of an instrument panel of an airplane provided with interlocking throttle and fuel valve controls according to the invention.

Fig. 2 is a side elevation partly in section, on a vertical central plane through Fig. 1, showing the parts in interlocking position.

Fig. 3 is a similar view showing the parts in flight position.

Figs. 4 and 5 are front elevation of a portion of an instrument panel of an airplane provided with a modified embodiment of the invention, with the parts in flightand interlocked-position, respectively, and Fig. 6 is a side elevation of the structure of Fig. 5 partly in section with respect to the panel mounting elements.

The conventional two or four place airplane is ordinarily provided with one throttle rod or handle placed midway in the instrument panel so that it is available from either side. This throttle control is usually a simple shaft or rod with a handle attached and reciprocable through the instrument panel. To open the throttle the handle is pushed inwardly toward the instrument panel. To close it the handle is pulled outwardly toward the pilot. For purposes of illustration the present invention is shown in the drawings as applied to this conventional form of throttle control.

In the illustrative embodiment of Figs. 1 to 3, the fuel valve control handle I0 is preferably associated directly with the throttle control H which is shown in the form of a rod provided with the usual knob or handle l2 at its outer end. In this arrangement the control handle I0 is carried by a sleeve [3 which is rotatably mounted in a bushing l4 carried by the instrument panel l5. Secured to sleeve I3 behind the panel [5, in any suitable manner, as by set screw I 6 is a drive pinion [1, which meshes with a driven pinion l8 secured on the stem IQ of a fuel cut-ofi valve 20, shown in Fig. 2 as of the rotary plug type, and interposed in the main fuel supply line 2|. The cut-off valve 20, in the form shown, is suitably supported, as by securement to a structural element of the instrument panel 22, for example, by bolts 23, which in the form shown, also secure in place a spline-plate 24 engaging with spline grooves 25 in the throttle control rod II to prevent rotation of the throttle rod for the purpose hereinafter described. I

The structure thus far described provides a throttle control lI-l2 for controlling the speed of the engine of the aircraft, a fuel line 2| for conducting fuel to said engine, a cut-off valve 20 in the fuel line, and means, in the form of handle In which is coupled through sleeve l3 and gear train l1-l8 for moving the cut-off valve to open and closed positions to control the flow of gasoline from the fuel tanks through pipe 2| to the carburetor of the engine.- As shown in Fig. 1, suitable legends may be provided for the guidance of the pilot in manipulating the controls, such legends being engraved on the instrument panel or control knobs, as desired.

In accordance with the invention the structure above described is further provided with an interlock controlled by the movement of the valve moving means If! and arranged to prevent movement of the throttle control ll-I2 from its closed throttle position (Fig. 2) to its open throttle or take-off position (Fig. 3) when the cut-off valve 20 is in its closed position.

As shown in Figs. 2 and 3, this interlock may take the form of a latch comprising the springpressed bolt or detent member 30, herein housed,

with its spring 3|, in a transverse bore 32 within the handle ID. Since the rod H passes through sleeve l3, and bore 32 is transverse of this sleeve, assembly is facilitated as the spring and bolt, inserted in bore 32, are held in place therein by insertion of the rod H. The latch, of course, further comprises a keeper, herein formed as an abutment 33 provided by a notch or recess 34 formed in the side of the throttle control rod I l in position to be engaged by bolt 30 when the throttle control ll, [2 and fuel valve 20 are both in closed position (Fig. 2). In this form of the invention, in which the throttle control rod H passes through the bore of the sleeve l3 through which the cut-off valve 28 is operated, rotation of sleeve [3, as will be apparent from Fig. 3, moves bolt 39 to an inoperative position, mis aligned with recess 34, as soon as the fuel valve handle H) is moved to practically full open position. To assure this action means is provided to prevent rotation of the throttle control rod ll, this means, as above described, comprising the spline plate 24 engaging with spline grooves 25, or the like. As shown in Figs. 2 and 3, in this arrangement it is preferable to arch somewhat the bottom of the recess 34, as this insures smoother working of the parts. The abutment 33, as shown, may be positioned to allow suflicient opening of the throttle for starting and slow running of the engine without opening of the fuel valve 20.

With the arrangement of Figs. 1 to 3, it will be appreciated that the fuel supply may be cut off by manipulation of the handle ll) while the throttle is in open position. Thus, on landing,

the fuel valve 20 may be closed and the engine may be operated at full taxiing speed on the residual gasoline in the carburetor and lines until the latter is exhausted, thus effecting quick draining of the lines and carburetor to facilitate servicing thereof, and to reduce fire hazard. If Y this is not done on landing, so that the carburetor and lines retain their fuel content, the engine may be started without moving the throttle control to full closed position. However, on starting of the engine under these circumstances, the natural reaction of the pilot is to pull out the throttle to slow-speed or idling position, whereupon latching of bolt 39 behind the abutment 33 occurs, preventing movement of the throttle to take-off position until the fuel valve control Ill, i3, is moved to open the valve 20.

When it is not desired to provide for quick draining of the carburetor and lines as above described, forms of the invention not providing for this feature may be employed. One such form is shown in Figs. 4 to 6. In this instance, the fuel valve control 40 is in the form of a slide member and is associated with the throttle control 4! having the usual knob or handle 42 at its outer end. In this arrangement the slide 40 is suitably supported, as by studs or the like 43, which are slidably mounted in slots 44 formed in the instrument panel 45. Suitable means is provided for associating the slide 48 with the fuel cut-off valve to be operated thereby, herein illustrated as a driving rack 41 secured on certain of studs 43, as by nuts 46 (see Fig. 6) and meshing with a driven pinion 48 secured on the stem 49 of the fuel cut-ofi valve which may be suitably supported in any desired manner, that indicated in connection with valve 20 and supporting means 2223 in Fig. 2 being suitable, for example. As above mentioned, suitable legends may be applied for the guidance of the pilot in manipulating the controls (see Figs. 4 and 5).

The interlock in this arrangement is efiected by providing the slide-member 40 with a projecting bolt, and preferably two such bolts in the form of a bifurcated end 50, adapted to be moved by movement of the slide 40 (which may be provided with the finger-hold 5| to facilitate its movement) into engagement behind shoulderor keeperabutment means 53 (Figs. 4 and 6) provided by recesses 54 milled or otherwise formed in the sides of throttle control rod 4|.

In this form of the invention, it will be apparent, slide 40 can be moved to turn the valve stem 43 to closed position only when the throttle control 41-42 is moved to closed position. This arrangement thus makes it impossible to turn off the fuel supply by moving the normal cutofi slide 40 while the throttle is in flight position. Similarly, throttle control 4l--42 is locked in closed, or nearly closed position, whenever the fuel valve is in closed position. This arrangement thus provides a two-way interlock and insures against cutting off the fuel supply while the airplane is in operation, as well as insuring against take-off of the airplane without opening of the fuel valve. In addition, by arranging the parts so that the ends of fork 50 are withdrawn from the notches 54 only when the slide 40 is moved to substantially full-open position, as shown, insurance is afforded against faulty operation due to restriction of the fuel supply by failure to fully open the cut-off valve.

From the foregoing it will be apparent that the embodiments shown and described are but illustrative and not restrictive of the invention herein described and claimed, and that inventive features and combination of this disclosure may be embodied in other specific forms.

I claim:

1. A safety device for an airplane of the type having a longitudinally reciprocable throttle rod for controlling the speed of the engine of the airplane and longitudinally movable from a closed or engine idling position to a substantial- 1y open position permitting take-off of the airplane, a fuel line for supplying fuel to the engine of the airplane, a valve in said fuel line, and means for moving said valve to open and closed positions; said safety device comprising an interlock controlled by the movement of said valvemoving means, which, in the closed position of said valve, intercepts said longitudinally reciprocable throttle rod in its closed or engine idling position and prevents its longitudinal movement to said substantially open take-off position, and which, when said valve has been opened and said throttle has been moved to its substantially open position, is incapable of preventing longitudinal movement of said throttle to its closed or engine idling position.

2. An airplane safety device according to claim 1, said interlock comprising a latch having a bolt and a keeper adapted to interengage to lock said throttle in its closed throttle position, said bolt in the open position of said fuel valve being moved to an inoperative position with respect to said keeper.

3. An airplane safety device according to claim 1, said interlock comprising a latch having a spring pressed bolt and a keeper adapted to interengage to lock said throttle in its closed throttle position, said bolt in the open position of said fuel valve being moved to an inoperative position misaligned with respect to said keeper.

4. An airplane safety device according to claim 1, said interlock comprising a bolt member movable by said valve moving means, a keeper abutment movable with said throttle. said keeper abutment preventing closing of said valve when said throttle is in said substantially open takeoif position, and said slide member preventing movement of said throttle to said substantially open take-ofi position when said valve is closed.

5. A safety interlock for preventing opening of the throttle of an airplane engine when the fuel cut-off valve between the fuel tanks and the carburetor of, the engine is closed; said interlock comprising a reciprocating throttle rod for opening and closing the throttle of the engine, a member for actuating the fuel cut-01f valve between the fuel tanks and the carburetor of the engine, said cut-off valve actuating member being juxtaposed to said reciprocating throttle rod, a bolt carried by said valve actuating member and moved to locking position by the movement of said valve actuating member to valve closing position, a notch formed in said throttle rod and located to align with said bolt when said throttle rod is in throttle closing position, said bolt entering said notch when both said valve actuating member and said throttle rod are in their respective valve-closing and throttle closing positions.

6. A safety interlock for preventing opening of the throttle of an airplane engine when the fuel cut-off valve between the fuel tanks and the carburetor of the engine is closed; said interlock comprising a bushing, valve actuating means comprising an actuating sleeve journalled in said bushing and rotatable therein for opening and closing the fuel cut-ofi valve between the fuel tanks and the carburetor of the engine and means for rotating said sleeve to valve opening and valve closing positions, a reciprocating throttle rod slidable in said sleeve for opening and closing the throttle of the engine, a springpressed bolt housed within said valve actuating means and bearing against said throttle rod, said throttle rod having a notch entered by said bolt when both said valve actuating means and said throttle rod are in their respective valve-closin and throttle closing positions. 1

7. A safety interlock for preventing opening of the throttle of an airplane engine when the fuel cut-off valve between the fuel tanks and the carburetor of the engine is closed; said interlock comprising a bushing, valve actuating means comprising an actuating sleeve journalled in said bushing and rotatable therein for opening and closing the fuel cut-01f valve between the fuel tanks and the carburetor of the engine and means for rotating said sleeve to valve opening and valve closing positions, a reciprocating throttle rod slidable in said sleeve for opening and closing the throttle of the engine, means locking said rod against rotation, a spring-pressed bolt housed within said valve actuating means and bearing against said throttle rod, said throttle rod having a notch formed in its side and having an arched bottom, said notch being entered by said bolt when both said valve actuating means and said throttle rod are in their respective valve-closing and throttle closing positions and being disengaged from said bolt on turning of said valve actuating means about said rod.

8. A safety interlock for preventing opening of the throttle of an airplane engine when the fuel cut-off valve between the fuel tanks and the carburetor of the engine is closed; said interlock comprising a panel element, a throttle rod reciprocable therethrough for opening and closing the throttle of the engine, said rod having a keeper abutment lying forwardly of the panel element in the throttle-closing position of the rod, a bolt member lying forwardly of the panel element,

said bolt member positioned to be movable to engage and disengage said abutment, a valve actuating member for opening and closing the fuel cut-oif valve between the fuel tanks and the carburetor of the engine, and a connection by which said valve actuating member moves said bolt to engage said abutment when said valve actuating member is moved to close the fuel cutoff valve.

MATT V. PILCHER.

aaraaanoss CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 396,548 Dexter Jan. 22, 1889 1,092,426 Bosse Apr. 7, 1914 1,169,659 Lowell Jan. 25, 1916 1,309,295 Magee July 8, 1919 1,471,515 Eulitt Oct. 23, 1923 2,224,290 Corbin Dec. 10, 1940 2,351,485 Conkle June 13, 1944 

